Modulations of the Chicken Cecal Microbiome and Metagenome in Response to Anticoccidial and Growth Promoter Treatment

With increasing pressures to reduce or eliminate the use of antimicrobials for growth promotion purposes in production animals, there is a growing need to better understand the effects elicited by these agents in order to identify alternative approaches that might be used to maintain animal health. Antibiotic usage at subtherapeutic levels is postulated to confer a number of modulations in the microbes within the gut that ultimately result in growth promotion and reduced occurrence of disease. This study examined the effects of the coccidiostat monensin and the growth promoters virginiamycin and tylosin on the broiler chicken cecal microbiome and metagenome. Using a longitudinal design, cecal contents of commercial chickens were extracted and examined using 16S rRNA and total DNA shotgun metagenomic pyrosequencing. A number of genus-level enrichments and depletions were observed in response to monensin alone, or monensin in combination with virginiamycin or tylosin. Of note, monensin effects included depletions of Roseburia, Lactobacillus and Enterococcus, and enrichments in Coprococcus and Anaerofilum. The most notable effect observed in the monensin/virginiamycin and monensin/tylosin treatments, but not in the monensin-alone treatments, was enrichments in Escherichia coli. Analysis of the metagenomic dataset identified enrichments in transport system genes, type I fimbrial genes, and type IV conjugative secretion system genes. No significant differences were observed with regard to antimicrobial resistance gene counts. Overall, this study provides a more comprehensive glimpse of the chicken cecum microbial community, the modulations of this community in response to growth promoters, and targets for future efforts to mimic these effects using alternative approaches

Satisfaction with Life after Mild Traumatic Brain Injury: A TRACK-TBI Study

Identifying the principal determinants of life satisfaction following mild TBI (mTBI) may inform efforts to improve subjective well-being in this population. We examined life satisfaction among participants in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study who presented with mTBI (Glasgow Coma Scale [GCS] score = 13-15; n = 1152). An L1-regularization path algorithm was used to select optimal sets of baseline and concurrent symptom measures for prediction of scores on the Satisfaction with Life Scale (SWLS) at 2 weeks and 3, 6, and 12 months post-injury. Multi-variable linear regression models (all n = 744-894) were then fit to evaluate associations between the empirically selected predictors and SWLS scores at each follow-up visit. Results indicated that emotional post-TBI symptoms (all b = -1.27 to -0.77, all p < 0.05), anhedonia (all b = -1.59 to -1.08, all p < 0.01), and pain interference (all b = -1.38 to -0.89, all p < 0.001) contributed to the prediction of lower SWLS scores at all follow-ups. Insomnia predicted lower SWLS scores at 2 weeks, 3 months, and 6 months (all b = -1.11 to -0.83, all ps < 0.01); and negative affect predicted lower SWLS scores at 2 weeks, 3 months, and 12 months (all b = -1.38 to -0.80, all p < 0.005). Other post-TBI symptom domains and baseline socio-demographic, injury-related, and clinical characteristics did not emerge as robust predictors of SWLS scores during the year after mTBI. Efforts to improve satisfaction with life following mTBI may benefit from a focus on the detection and treatment of affective symptoms, pain, and insomnia. The results reinforce the need for tailoring of evidence-based treatments for these conditions to maximize efficacy in patients with mTBI

Invariance of the Bifactor Structure of Mild Traumatic Brain Injury (mTBI) Symptoms on the Rivermead Postconcussion Symptoms Questionnaire Across Time, Demographic Characteristics, and Clinical Groups: A TRACK-TBI Study

This study aimed to elucidate the structure of the Rivermead Postconcussion Symptoms Questionnaire (RPQ) and evaluate its longitudinal and group variance. Factor structures were developed and compared in 1,011 patients with mild traumatic brain injury (mTBI; i.e., Glasgow Coma Scale score 13-15) from the Transforming Research and Clinical Knowledge in TBI study, using RPQ data collected at 2 weeks, and 3, 6, and 12 months postinjury. A bifactor model specifying a general factor and emotional, cognitive, and visual symptom factors best represented the latent structure of the RPQ. The model evinced strict measurement invariance over time and across sex, age, race, psychiatric history, and mTBI severity groups, indicating that differences in symptom endorsement were completely accounted for by these latent dimensions. While highly unidimensional, the RPQ has multidimensional features observable through a bifactor model, which may help differentiate symptom expression patterns in the future

ATTENUATING MUSCLE ATROPHY USING ESSENTIAL AMINO ACID SUPPLEMENTATION BEFORE AND AFTER TOTAL KNEE ARTHROPLASTY

C. Policar1, L. Wheary1, M. Barnes1, J. Agtarap1, E. Owen2, T. Kirkpartick2, A. Poluso2, M. Bremer2, L. Strycker3, K. Smolkowski3, B. Lantz4, S. Shah4, C. Mohler4, B. Jewett4, J. Muyskens1, H. Dreyer1 1University of Oregon; 2Slocum Research and Education Foundation; 3Oregon Research Institute;4Slocum Center for Orthopedics and Sports Center, Eugene, OR PURPOSE: The demand for total knee arthroplasty (TKA) is projected to increase nearly seven-fold to 3.4 million surgeries performed annually in the U.S. by 2030. A proof-of-principle report by our group recently showed that essential amino acid (EAA) supplementation before and after TKA was successful in mitigating muscle atrophy after surgery vs.Placebo. The present investigation, conducted with a larger number of subjects having a wider age range (50-80 vs.60-80 y) and under the care of more surgeons, sought to repeat that study. METHODS: Using a double-blind placebo-controlled randomized clinical trial, 39 older adults (age 50-80 y) having TKA were randomized to ingest either 20 g of EAA (n = 19) or Placebo (n = 20) 2x/d between meals for 1 wk before, and 6 wk after TKA. At baseline, 2 wk post-TKA and 6 wk post-TKA, an MRI was obtained to determine mid-thigh muscle and adipose tissue volume; MRI scans were obtained at the Lewis Center for Neuroimaging. RESULTS: At 6 wk post-TKA, quadriceps muscle atrophy was significantly greater in the Placebo group in the operative leg quadriceps (-13.4%±1.9 [M±SE] change from baseline for Placebo vs.-8.5%±2.5 for EAA;p= .033) and in the non-operative leg quadriceps (-7.2%±1.4 change for Placebo vs.-1.5%±1.6 for EAA; p = .014). Similar results were found for the hamstrings, in the operative leg (-12.2%±1.4 change for Placebo vs.-7.4%±2.0 for EAA;p = .036) and in the non-operative leg (-7.5%±1.5 change for Placebo vs.-2.1%±1.3 for EAA;p = .005). Effect sizes (d) were .34, .68, .41, and .67 for operative quadriceps, non-operative quadriceps, operative hamstrings, and non-operative hamstrings, respectively. CONCLUSIONS: Twice-daily ingestion of 20 g of EAA for 7 d before and 42 d after (49 d total) TKA demonstrated muscle-sparing effects in the operative and non-operative quadriceps and hamstrings at 6 wk post-TKA. NIA:R01AG04640

Invariance of the Bifactor Structure of Mild Traumatic Brain Injury (mTBI) Symptoms on the Rivermead Post-Concussion Symptoms Questionnaire across Time, Demographic Characteristics, and Clinical Groups: A TRACK-TBI Study

This study aimed to elucidate the structure of the Rivermead Postconcussion Symptoms Questionnaire (RPQ) and evaluate its longitudinal and group variance. Factor structures were developed and compared in 1,011 patients with mild traumatic brain injury (mTBI; i.e., Glasgow Coma Scale score 13-15) from the Transforming Research and Clinical Knowledge in TBI study, using RPQ data collected at 2 weeks, and 3, 6, and 12 months postinjury. A bifactor model specifying a general factor and emotional, cognitive, and visual symptom factors best represented the latent structure of the RPQ. The model evinced strict measurement invariance over time and across sex, age, race, psychiatric history, and mTBI severity groups, indicating that differences in symptom endorsement were completely accounted for by these latent dimensions. While highly unidimensional, the RPQ has multidimensional features observable through a bifactor model, which may help differentiate symptom expression patterns in the future

Satisfaction with Life after Mild Traumatic Brain Injury: A TRACK-TBI Study

Identifying the principal determinants of life satisfaction following mild TBI (mTBI) may inform efforts to improve subjective well-being in this population. We examined life satisfaction among participants in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study who presented with mTBI (Glasgow Coma Scale [GCS] score = 13-15;  = 1152). An L1-regularization path algorithm was used to select optimal sets of baseline and concurrent symptom measures for prediction of scores on the Satisfaction with Life Scale (SWLS) at 2 weeks and 3, 6, and 12 months post-injury. Multi-variable linear regression models (all  = 744-894) were then fit to evaluate associations between the empirically selected predictors and SWLS scores at each follow-up visit. Results indicated that emotional post-TBI symptoms (all b = -1.27 to -0.77, all  < 0.05), anhedonia (all b = -1.59 to -1.08, all  < 0.01), and pain interference (all b = -1.38 to -0.89, all  < 0.001) contributed to the prediction of lower SWLS scores at all follow-ups. Insomnia predicted lower SWLS scores at 2 weeks, 3 months, and 6 months (all b = -1.11 to -0.83, all s < 0.01); and negative affect predicted lower SWLS scores at 2 weeks, 3 months, and 12 months (all b = -1.38 to -0.80, all  < 0.005). Other post-TBI symptom domains and baseline socio-demographic, injury-related, and clinical characteristics did not emerge as robust predictors of SWLS scores during the year after mTBI. Efforts to improve satisfaction with life following mTBI may benefit from a focus on the detection and treatment of affective symptoms, pain, and insomnia. The results reinforce the need for tailoring of evidence-based treatments for these conditions to maximize efficacy in patients with mTBI